Electrode for a vapor electric device and method of constructing the same



June 25, 1935. N E 2,005,897

ELECTRODE FOR A VAPOR ELECTRIC DEVICE AND METHOD OF CONSTRUCTING THE SAME Filed Sept. 27, 1933 Fig.1.

WITNESSES: INVENTOR Dewe D. Knawles ATTORNEY Patented June 25, 1935 ELECTRODE FOR A PATENT OFFICE VAPOR ELECTRIC DEVICE AND METHOD OF CONSTRUCT- ING THE SAME Dewey n. Knowles, Wilkinsburg, Pa, assignor to Westinghouse Electric 8: Manufacturing Com-- pany, East Pittsburgh, Pa acorporation of Pennsylvania Application September 27, 1938, Serial No. 891,153

6 Claims. (01. 250-275) My invention relates to an electrode for a vapor electric device and method of constructing the same.

In the operation of vapor electric converters it has been found advantageous to employ an electrode of resistance material to initiate a cathode spot at the beginning of each conducting period in the rectifier. Considerable difflculty has been experienced with such electrodes due to the fragile nature of the material utilized. It is desirable to construct such make-alive electrodes of a tip of igniter material supported on a suitable metallic stem.

Considerable difliculty has been experienced in providing a suitable connection between the igniter material and the metallic stem. Because of the irregular nature of the igniter material, clamps have proven unsatisfactory because of the poor contact between the clamp and the electrode tip and also because of the mechanical pressure which frequently crushes or otherwise damages the tip material, causing it to fall out or disintegrate during the operation of the device.

It is an object of my invention to provide an electrode in which there will be suitable mechanical and electrical contact between the electrode stem and the igniter material without the necessity of the application of damaging mechanical forces to the igniter material.

It is a further object of my invention to provide a method of constructing such an electrode.

In the electrode according to my invention the stem and terminal are placed in the desired relationship and connected by spraying a suitable layer of molten metal over the junction between the stem and terminal.

Other objects and advantages of my invention will be apparent from the following detailed description, when taken in conjunction with the accompanying drawing, in which:

Figure 1 is an elevation of the components of an electrode according to my invention.

Fig. 2 is a similar view showing the electrode tip and the stem wrapped with a metallic element to mechanically hold the same in place;

Fig. 3 is a schematic illustration of the method of applying a molten material; and,

Fig. 4 is an elevation, partially in section, of my finished electrode.

In the construction of an electrode according to my invention, a suitable electrode stem I com posed of a metal, such as iron or nickel, substantially unefiected by mercury is placed in end to end relation with a suitable section 2 of igniter material such as carborundum, boron, boron carbide, etc. I

While these elements may be held in suitable relationship by any desired means, I prefer to hold them by a wrapping of a suitable metallic element 3 such as nickel wire.

While held in the desired relationship molten metal. such as iron or nickel or other metal substantially uneifected by mercury, is sprayed in a substantially uniform layer 4 of such a length as to embrace a portion of the stem and of the terminal. This layer 4 is preferably supplied in the molten condition by a blast of heated gases such as produced by the schoup gun 6.

The layer 4 of deposited material is made of such thickness as to readily mechanically support the terminal 2 in a desired relationship to the electrode stem I. Because of the molten condition in which the metal I is applied to the joint, it will be in intimate contact with both the stem and the terminal material, and consequently, provide good electrical contact, as well as mechanical support for the terminal element.

While for purposes of illustration I have described a specific embodiment of my invention,

it will be apparent to those skilled in the art that changes and modifications can be made therein without departing from the true spirit of my invention or the scope of the appended claims.

I claim as my invention:

1. The method of securing an electrode head to a stem which comprises placing the head and stem in the desired position with respect to each other, winding adjacent portions of the head and stem with wire and spraying a layer of metal over that portion wrapped with the wire.

2. The method of constructing an electrode for a mercury-arc converter which comprises providing a ferrous metal stem, a head of resistance material, placing said head and stem in the desired relation, wrapping a portion of said head and stem with wire and spraying the wrapped portion with nickel for providing a permanent connection.

3. An electrode for a vapor-electric device comprising a stem of ferrous material, a head of resistance material, and a sheath of sprayed nickel embracing a portion of said head and said stem.

4. The method of constructing an electrode for a mercury-arc converter which comprises providing a stem for a metal substantially unaffected by mercury and a head of carborundum, placing said head and stem in desired relation, winding a metallic element about a portion of said head and stem for securing them in said relation and spraying a layer 01' metal substantially unailected by mercury on said head and stem.

5. The method of constructing an electrode which comprises providing a stem and a head of carbonmdum, placing said head and said stem in abutting relation and spraying a layer 01' molten metal on the abutting ends of said stem and head for electrically and mechanically connecting the same.

'6. The method of securing non-metallic electrode heads to metallic stems which comprises holding the head and stem in contact with each other and spraying molten metal on said head an stem at the point 0! contact.

. DEWEY D. KNOWLES. 

